Carbon nanotubes offer attractive possibilities for developing new sensors because of superior mechanical and electrical properties. So far most studies relate the mechanical deformation to the change of nano-scale electrical properties.
We present an attempt to use the multi-wall carbon nanotubes (MWCNT) to develop a new material for sensing macro-scale strain. Polymer composites containing dispersed nano-size particles, for example, polyisoprene -multi-wall carbon nanotube composites (PMCNTC) were prepared by treatment of the composite matrix with chloroform providing an increase of mobility and better dispersion of the nano-particles within the matrix. MWCNT with a small amount of solvent was carefully ground in a china pestle before adding to the polyisoprene matrix. Both the polyisoprene matrix solution and concentrated MWCNT product were mixed in a mixer with small glass beads at room temperature for 15 min. The product was dried at 40 °C for over 12 h and vulcanized under high pressure at 160 °C for 20 min. PMCNTC shows attractive tensile and compressive strain sensing properties. A mechanism of sensing effects is being investigated.